Embodiments described herein generally relate to fertilizers. More particularly, such embodiments relate to reaction products that provide an extended period of nitrification inhibition and methods for making and using the same.
Fertilizers typically include urea, ammonia, ammonium nitrate, or a mixture thereof to provide a source of nitrogen. Nitrogen is a vital nutrient for plant growth. When urea is used as a source of nitrogen in the fertilizer, the urea converts to ammonia as a result of hydrolysis catalyzed by urease, which is an enzyme produced by numerous fungi and bacteria found in the soil. Ammonia rapidly undergoes ionization in the soil to form ammonium. In most soils, the resulting ammonium and the ammonium nitrate, if present, are readily oxidized to nitrate (NO3) via a sequence of bacterial oxidation reactions, which is commonly referred to as “nitrification.” Nitrification of the ammonium, however, happens so fast that a large percentage of the nitrogen in the fertilizer is lost before the plants can utilize it.
Nitrogen is also lost from the soil through volatilization to the atmosphere. Nitrate, another source of nitrogen, is typically lost through leaching into the subsoil by rainwater and/or through denitrification, i.e., bacterial conversion of nitrate to elemental nitrogen.
Attempts to reduce such losses of nitrogen have utilized urease inhibitors and/or nitrification inhibitors as additives to the fertilizer. Urease inhibitors are compounds capable of inhibiting the catalytic activity of the urease enzyme on urea in the soil. Nitrification inhibitors are compounds capable of inhibiting the bacterial oxidation of ammonium to nitrate in the soil. Nitrification inhibitors, however, tend to leach into the soil, away from the plant, thus becoming ineffective at inhibiting nitrification where it is needed-near the plant.
There is a need, therefore, for improved fertilizers that provide an extended period of nitrification inhibition and methods for making and using the same. There is also a need for improved products that reduce nitrification in soil and methods for making and using the same.